Systems and methods for procesing data entered using an eye-tracking system

ABSTRACT

A method for processing data entered using an electronic device and an electronic device capable of implementing the method is described. In one embodiment, the electronic device includes at least one multi-value key associated with at least two input data values. Each multi-value key includes a plurality of units and each input data value corresponds to at least one unit. The electronic device also includes an eye-tracking system that determines an area where a user is gazing by monitoring eye movements of the user, and an input value selection module coupled to the plurality of units and to the eye-tracking system. The input value selection module determines probabilistically which input data value was entered based on a value received from at least one unit and on the area where the user is gazing.

FIELD OF THE INVENTION

The present invention relates to electronic devices, and moreparticularly to a system for processing data entered at an electronicdevice.

BACKGROUND

Handheld electronic devices, such as mobile phones, cameras and personaldigital assistants (PDAs), offer a multitude of services and functions.For example, with the development of wireless technologies, manyhandheld devices are capable of connecting a user to a wireless network,such as the Internet, and allowing the user to send and receiveinformation to and from other users via the wireless network. Moreover,many handheld devices can load and run software applications that allowthe user to perform computing tasks.

While handheld devices can offer performance and versatility, theavailable services can sometimes be awkward to use because of device'ssize. Of particular concern is data entry, e.g., inputting text for anelectronic message. Most handheld devices lack the space to provide afull keyboard for entering data and instead utilize several knowntechniques to allow the user to create words or number patterns.Nevertheless, each technique has its disadvantages.

For example, mobile phones typically provide a conventional number-keypad where each number key, i.e., key 2-9, is associated with three tofour alphanumeric characters. By pressing specific keys, the user canform words. One method for creating words using the number-key pad usesa prediction algorithm that relies on an electronic dictionary of commonwords to predict a word based on the key(s) pressed. This technique,referred to as the T-9 technique, allows the user to tap a key, and ainput value selection module in the device checks the dictionary toresolve ambiguities between the letters associated with the tapped key.Although the T-9 technique is a single-tap method that can allow fastdata entry, it is not intuitive and can be deficient when two or morewords are formed by the same sequence of tapped keys. In that instance,the T-9 technique cannot disambiguate between the words themselves andthe user must resolve the ambiguity.

Another word forming technique using the number-key pad is referred toas multi-tapping. In multi-tapping, the user enters a particular letterby pressing the number key associated with the letter at least one timeto scroll to the desired letter. Once the desired letter is found, e.g.,displayed on the screen, the user must wait until the selection iscommitted and the letter is inputted before proceeding to the nextletter. While multi-tapping allows the user to form words withoutambiguity, it is time-consuming and awkward.

Other handheld devices, such as PDAs, can display a full keyboard on atouch screen, and the user selects letters by touching or tapping on thetouch screen with a stylus. In other similar devices, a full miniaturekeyboard is provided in the device itself. In both instances, the sizeof the displayed and physical keyboard is reduced to accommodate thespace limitations. Because the keys are small, they are difficult to seeor press, making text entry awkward and slow as well as error prone.

Other text entry techniques exist but suffer from the same and othershortcomings described above. Most of these techniques, in addition tobeing awkward and slow, are not intuitive and/or require the user tospend much time practicing in order to become somewhat proficient.

SUMMARY

The present invention provides a method and system for entering datausing an eye-tracking system in combination with a plurality of manuallyactivated keys. In one embodiment, an electronic device includes atleast one multi-value key associated with at least two input datavalues. Each multi-value key includes a plurality of units and eachinput data value corresponds to at least one unit. The electronic devicealso includes an eye-tracking system that determines an area where auser is gazing by monitoring eye movements of the user, and an inputvalue selection module coupled to the plurality of units and to theeye-tracking system. The input value selection module determinesprobabilistically which input data value was entered based on a valuereceived from at least one unit and on the area where the user isgazing.

In another embodiment, the electronic device includes a plurality ofdata input keys. Each input key is associated with at least one inputdata value and at least one data input key is a multi-value keyassociated with at least two input data values. The electronic devicealso includes an eye-tracking system that determines an area where auser is gazing by monitoring eye movements of the user and thatdetermines an area covering portions of at least two data input keys, atleast one of which is a multi-value key. The electronic device alsoincludes an input value selection module coupled to the plurality ofdata input keys and to the eye-tracking system that determines whichinput data value was entered based on a manually pressed data input keyand on the area where the user is gazing.

In another embodiment, a method for processing data entered at anelectronic device having at least one multi-value key associated with atleast two input data values includes assigning a plurality of units toeach multi-value key, where each input data value corresponds to atleast one unit, determining an area where a user is gazing by trackingthe user's eye movement, detecting a manual selection of a multi-valuekey, and determining probabilistically which input data value wasentered based on a value received from at least one unit and on the areawhere the user is gazing.

In another embodiment, a method for processing data entered at anelectronic device having a plurality of data input keys, where each datainput key is associated with at least one input data value and at leastone data input key is a multi-value key associated with at least twoinput data values, includes determining an area where a user is gazingby tracking the user's eye movement, where the area covers portions ofat least two data input keys, at least one of which is a multi-valuekey, detecting a manual selection of a data input key, and determiningwhich input data value was entered based on the manually pressed datainput key and on the area where the user is gazing.

DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The various features of the present invention and the manner ofattaining them will be described in greater detail with reference to thefollowing description, claims and drawings, wherein reference numeralsare reused, where appropriate, to indicate a correspondence between thereferenced items, and wherein:

FIG. 1A is a schematic diagram of an exemplary electronic deviceaccording to an embodiment;

FIG. 1B is a system block diagram of the electronic device according toan embodiment;

FIGS. 2A, 2B and 2C illustrate an exemplary multi-value key that isassociated with four (4) input values according to an embodiment;

FIG. 3 is a flowchart illustrating a process for processing data enteredat the electronic device according to an embodiment shown in FIGS. 1A,1B, and 2A-2C;

FIG. 4 is a flowchart illustrating a process for calculating theprobability factor for an input value according to one embodiment;

FIG. 5 is a schematic diagram of an exemplary electronic deviceaccording to another embodiment;

FIG. 6 is an illustration for a group of four (4) multi-value input keysaccording to an embodiment; and

FIG. 7 is a flowchart illustrating a process for processing data enteredat the electronic device according to the embodiment shown in FIGS. 5and 6.

DETAILED DESCRIPTION

The present invention relates to electronic devices, and moreparticularly to methods and systems for processing data entered at anelectronic device. The following description is presented to enable oneof ordinary skill in the art to make and use the invention and isprovided in the context of a patent application and its requirements.Various modifications to the preferred embodiments and the genericprinciples and features described herein will be readily apparent tothose skilled in the art. Thus, the present invention is not intended tobe limited to the embodiments shown, but is to be accorded the widestscope consistent with the principles and features described herein.

According to one embodiment, an eye-gaze or eye-tracking system isincorporated into an electronic device that has data input keys that areassociated with two or more input values. The electronic device uses theeye-tracking system to determine where a user is gazing while the userpresses a data input key. Based on the eye-tracking and key press data,the electronic device is able to determine which of the two or moreinput values associated with the pressed key was entered.

FIG. 1A is a schematic diagram of an exemplary electronic deviceaccording to an embodiment and FIG. 1B is a system block diagram of theelectronic device according to another embodiment. Referring to FIGS. 1Aand 1B, the electronic device 10 includes a plurality of data input keys20, an eye-tracking system 40, an input value selection module 30, and adisplay screen 50. The data input keys 20 can be arranged in rows andcolumns to form a keypad 25 on a face 12 of the electronic device 10.Each data input key 20 is associated with at least one input value 22,and at least one of the data input keys is a multi-value key 20 a thatis associated with at least two data input values 22 a, 22 b, 22 c.

In a preferred embodiment, the eye-tracking system 40 is located on thesame face 12 of the electronic device as the keypad 25. The eye-trackingsystem 40 tracks and records the movement of a user's eye(s) todetermine an area where the user is gazing. The eye-tracking system 40can use many different known techniques to monitor and track the user'seye movements. For example, the eye-tracking system 40 can utilize atechnique known as corneal reflection, which directs an infrared lightbeam at the user's eye and measures the angular difference between theoperator's mobile pupil and the stationary light beam reflection.Alternatively, the eye-tracking system 40 can scan the user's eye regionwith a scanning apparatus, e.g., television camera, and analyze theresulting image. Commercially available eye-tracking systems 40 that canbe appropriate for the present invention include, for example, the QUICKGLANCE product developed by EyeTech Digital Systems of Mesa, Ariz.

In order to enter an input value, particularly one that is associatedwith a multi-value key 20 a, e.g., 22 a, the user locates the key 20 awith which the input value 22 a is associated and gazes at or near acorresponding representation of input value 22 a on the face of the keywhile pressing the key 20 a. The input value selection module 30receives the eye-tracking data as well as the data related to theselected, e.g., manually pressed, key 20 a, and analyzes the receiveddata to determine which input value 22 a was entered. The entered value22 a is then preferably displayed on a screen 50.

In one embodiment, the accuracy with which the input value selectionmodule 30 can determine the input value 22 a is improved by dividingeach multi-value key 20 a into a plurality of units and associating eachof the input values 22 a-22 c with at least one of the units. In apreferred embodiment, a representation of each input value is providedon a portion of the multi-value key that coincides with the associatedunit(s). Each unit, in turn is associated with at least one pressuresensor that is capable of measuring a pressure asserted on theassociated unit.

FIG. 2A is an illustration of an exemplary multi-value key 200 that isassociated with four (4) input values 202 a-202 d. As is shown in FIG.2B, the multi-value key 200 is divided into four (4) units 210 a-210 dand each of the input values 202 a-202 d is associated with one of thefour units 210 a-210 d. In FIG. 2B, the multi-value key 200 is dividedinto four (4) substantially equal units 210 a-210 d merely for the sakeof clarity. The number of units can be greater than four (4) and, insuch circumstances, each input value, e.g., 202 a, can be associatedwith more than one unit 210 a. Similarly, the shape and size of eachunit 210 can vary so long as each input value 202 a-202 d is associatedwith at least one unit 210.

As is shown in FIG. 2C, each unit 210 a-210 d may be associated with apressure sensor 220 a-220 d that is capable of quantifying the amount ofpressure asserted on the associated unit 210 a-210 d. Although not shownin FIG. 2C, each unit, e.g., 210 a, can be associated with more than onepressure sensor 220 a, and the shape and size of the pressure sensors220 a-220 d can vary.

According to this embodiment, during data entry, the user can press theportion of the multi-value key on which the desired input value, e.g.,202 a, is provided, while gazing at the desired input value 202 a. Eachpressure sensor 220 a-220 d measures the pressure asserted on itsassociated unit 210 a-210 d. The input value selection module 30receives the pressure measurements from each of the pressure sensors 220a-220 d along with the eye-tracking information and determines which ofthe associated input values 202 a-202 d was entered.

FIG. 3 is a flowchart illustrating a process for processing data enteredat the electronic device 10 shown in FIGS. 1 and 2. The process beginsby activating the keypad 25 (step 300), for example, by unlocking theinput keys 20. The activation of the keypad 25 can also activate theeye-tracking system 40, which then monitors and records the user's eyemovements (step 302). Activation of the keypad 25 and/or eye-trackingsystem 40 does not necessarily require an additional action or input,but can occur automatically when electronic device 10 is powered up.According to a preferred embodiment, the eye-tracking system 40 monitorsand records, among other things, an area where the user is gazing, whichinput value(s) are in the area, and the amount of time the user's gazerests on the input value(s).

When the user presses a multi-value key 200 (step 304) to enter adesired input value, e.g., 202 a, each pressure sensor 220 a-220 dmeasures the amount of pressure asserted on the associated unit 210a-210 d. The pressure measurements associated with each unit 210 a-210 dare received by the input value selection module 30, which assigns toeach input value 202 a-202 d a pressure weight, P, based on thecorresponding pressure measurement(s) (step 306). In one embodiment, thepressure weight, P, can be a fraction ranging from zero (0),corresponding to the lowest pressure measurement, to one (1.0),corresponding to the highest pressure measurement.

Thus, in the example above where the user wants to enter input value “2”(202 a), the user preferably presses at or near the upper left handcorner of the input key 200, which is the portion of the key on whichthe “2” is provided and which substantially coincides with the unit 210a associated with the input value 202 a. The pressure sensors 220 a-220d measure the pressure asserted on each of the units 210 a-210 d.Because the user presses the portion of the key 200 substantiallycoinciding with the unit 210 a corresponding to the desired input value202 a, the pressure weight, P, assigned to that input value 202 a willnaturally be greater than the pressure weight assigned to an inputvalue, e.g., 202 d, associated with a portion of the key 200 that wasnot pressed directly.

In addition to processing the pressure measurements, the input valueselection module 30 also analyzes the eye-tracking data to determine howlong the user was gazing at any of the input values 202 a-202 d prior topressing the key 200 and assigns a gaze weight, G, to each input value202 a-202 d based on the amount of time the user was gazing at the inputvalue 202 a-202 d (step 308). Like the pressure weight, P, the gazeweight, G, can be a fraction ranging from zero (0), corresponding to theleast amount of gaze time, to one (1.0), corresponding to the greatestamount of gaze time. Once the pressure weight, P, and gaze weight, G,for each input value 202 a-202 d are assigned, the input value selectionmodule 30 calculates a probability factor, PF, for each input value(step 310).

FIG. 4 is a flowchart illustrating a process for calculating theprobability factor for an input value, e.g., 202 a, according to oneembodiment. For each input value 202 a-202 d, the assigned pressureweight, P, and gaze weight, G, are added to form a combined weight, C(step 400). The combined weight, C, for each input value 202 a-202 d issummed to form a total weight, T (step 402). The probability factor, PF,for each input value 202 a-202 d is calculated by dividing the combinedweight, C, of the input value 202 a by the total weight, T (step 404).Thus, for an input value, i, the probability factor, PF(i) is determinedby:PF(i)=C(i)/T

Referring again to FIG. 3, after the probability factor for each of theinput values 202 a-202 d is calculated (step 310), the input valueselection module 30 selects the input value having the greatestprobability factor and displays that input value (step 312).

Based on the embodiment described above, the methods and systemsdisclosed take advantage of how the user intuitively enters data. Thatis, the user searches the keypad 25 for the key 20 that includes theinput value 22 the user desires to enter. When the user's gaze fallsupon the desired input value 22, the user instinctively focuses on theinput value 22 and presses the portion of the key 20 displaying theinput value 22. The various components of the electronic device 10according to this embodiment monitor these actions to allow the user toenter the desired input value. The user can enter the desired inputvalue with a single tap and need not wait a prescribed time beforeentering another input value. Accordingly, this embodiment is easy touse and provides fast data entry.

In another embodiment, illustrated in FIG. 5, the accuracy with whichthe input value selection module 30 can determine the input value 22 ais improved by defining a plurality of gaze areas 14 on the face 12 ofthe electronic device 10 a. According to this embodiment, each definedgaze area 14 covers a portion of at least two data input keys 20, andpreferably is associated with one input value in each of the at leasttwo data input keys 20. Moreover, in this embodiment, input valueselection module 30 can determine the input value 22 a even when eachinput key 20 includes only one input sensor that is associated withmultiple input values 202 a assigned to the input key 20. The inputsensor is activated when the associated input key 20 is pressed. Theinput sensor may be a simple momentary switch providing two binaryvalues (0 or 1) or may be a pressure sensor as described above.

For example, FIG. 6 is an illustration for a group of four (4)multi-value input keys 200 a-200 d according to this embodiment of thepresent invention. As is shown, one gaze area 14 a includes an areacorresponding to one input value of each of the four (4) keys 200 a-200d. Another gaze area 14 b includes a different area corresponding to adifferent set of input values in each of two (2) keys 200 c, 200 d. Thegaze areas 14 a, 14 b do not overlap, and therefore, any particularinput value, e.g., 202 d, is associated with only one gaze area 14 a.

Referring again to FIG. 5, each gaze area 14 can also include a focalpoint 16, which is preferably near the center of the gaze area 14. Thefocal point 16 can be a feature, such as a dot, so that the user canfocus on the point 16. Alternatively, the focal point 16 can be unmarkedand merely defined as near or around the center of the gaze area 14.Other ways of designating a gaze area 14 and its focal point 16 areavailable as those skilled in the art would readily appreciate.

Referring again to FIG. 6, during data entry, the user can press themulti-value key, e.g., 200 a, associated with the desired input value,e.g., 202 d, while gazing at or near the focal point 16 a associatedwith the gaze area 14 a. The input value selection module 30 receivesthe key press data along with the eye-tracking information anddetermines which of the input values 202 a-202 d associated with thepressed key 200 a was entered by selecting the input value 202 dassociated with the gaze area 14 a.

FIG. 7 is a flowchart illustrating a process for processing entered datausing the electronic device 10 according to the embodiment shown inFIGS. 5 and 6. The process begins by activating the keypad 25 (step700), for example, by unlocking the input keys 20 or by powering up theelectronic device 10. The activation of the keypad 25 can also activatethe eye-tracking system 40, which then monitors and records the user'seye movements (step 702). According to a preferred embodiment, theeye-tracking system 40 monitors and records, among other things, atwhich gaze area 14 the user is gazing and, optionally, an amount of timethe user is gazing at a particular gaze area 14. Preferably, the userfocuses on the focal point 16 of the gaze area 14 so that theeye-tracking system 40 can determine the gaze area 14 more accurately byincreasing the margin for error.

When the user presses a multi-value key 200 a (step 704) to enter adesired input value, e.g., 202 d, the input value selection module 30determines which input key 200 a was pressed (step 706) and determinesat which gaze area 14 a the user is gazing (step 708) during a timeperiod either immediately before and/or after the key 200 a was pressed.The time period can be short such that the gazing action issubstantially simultaneous with the key pressing event. On the otherhand, the time period can be longer to ensure that the input valueselection module 30 detects the correct gaze area 14 a. Once the gazearea 14 a and the pressed key 200 a are determined, the input valueselection module 30 displays the entered input value 202 d associatedwith both the pressed key 200 a and the gaze area 14 a (step 710).

This embodiment also takes advantage of how the user intuitively entersdata. That is, the user searches for the key 200 a that is associatedwith the desired input value 202 d and presses the key 200 a whilegazing at a designated focal point 16 a near the desired input value 202d. The user can enter the desired input value 202 d with a single tapand need not wait a prescribed time before entering another input value.Accordingly, this embodiment is also easy to use and provides fast dataentry.

Although the embodiments described above each utilize a keypad 25, theprinciples described herein can also be used with a standard sizedkeyboard that includes multi-value keys. For example, in a typicalQWERTY keyboard, the key associated with the input value “2” is alsoassociated with the character “@.” Utilizing the systems describedherein, the user can enter the character “@” by gazing at the “@” andtyping the key. In another example, foreign language keyboards oftenrequire the user to press a sequence of keys to enter a symbol. With thesystem of the present invention, the symbol can be associated with a keyand can be entered with a single tap.

Moreover, the aspects described herein can also be combined with otherletter prediction techniques, such as a word-based letter predictiontechnique that is based on a dictionary or an application-specific setof words. In this aspect, a word-based technique yields a probability Wfor a given letter, where the larger W is the more probable the givenletter. The probability factor PF calculated by the input valueselection module 30 can be combined with W to produce a combinedprobability weight CW. Depending on how PF and W are combined, eithertechnique can be given priority. For example, let CW=PF×W. Here, bothtechniques are given equal priority. Alternatively, let CW=(PF)^(1/n)×W.Here, the key-press-gaze technique is given higher priority than theword-based technique.

According to aspects described herein, single tap data entry is enabledby incorporating an eye-tracking system into an electronic device thathas data input keys that are associated with two or more input values.The electronic device uses the eye-tracking system to determine where auser is gazing while the user presses a data input key. Based on theeye-tracking and key press data, the electronic device is able todetermine which of the two or more input values associated with thepressed key was entered.

The present invention has been described in accordance with theembodiments shown, and one of ordinary skill in the art will readilyrecognize that there could be variations to the embodiments, and anyvariations would be within the spirit and scope of the presentinvention. Software written according to the present invention is to bestored in some form of computer-readable medium, such as memory, CD-ROMor transmitted over a network, and executed by a input value selectionmodule. Consequently, a computer-readable medium is intended to includea computer readable signal which, for example, may be transmitted over anetwork. Accordingly, many modifications may be made by one of ordinaryskill in the art without departing from the spirit and scope of theappended claims.

1. An electronic device comprising: at least one multi-value keyassociated with at least two input data values, wherein each multi-valuekey includes a plurality of units and each input data value correspondsto at least one unit; an eye-tracking system for determining an areawhere a user is gazing by monitoring an eye movement of the user; and aninput value selection module coupled to the plurality of units and tothe eye-tracking system; wherein the input value selection moduledetermines probabilistically which input data value was entered based ona value received from at least one unit and on the area where the useris gazing.
 2. The electronic device according to claim 1 furthercomprising: a plurality of pressure sensors coupled to the input valueselection module, wherein at least one pressure sensor is associatedwith each unit of the multi-value key and wherein each of the pressuresensors is configured to measure a pressure asserted on the associatedunit of the multi-value key; wherein the input value selection moduleconcurrently analyzes the pressure measurements and the area at whichthe user is gazing to determine which input data value was entered. 3.The electronic device of claim 2 wherein the input value selectionmodule is configured for: assigning a pressure weight to each of theinput data values associated with the multi-value key, the pressureweight corresponding to measured pressured asserted on the unitcorresponding to the input data value; assigning a gaze weight to eachof the input data values based on an amount of time that the area atwhich the user is gazing coincides with the unit corresponding to theinput data value; combining the pressure weight and the gaze weight ofeach input data value; and entering the input data value based on thecombined pressure and gaze weights.
 4. The electronic device accordingto claim 2 wherein the area at which the user is gazing substantiallycoincides with a unit associated with an input data value.
 5. Theelectronic device according to claim 1 wherein the electronic device isa handheld device.
 6. The electronic device according to claim 5 whereinthe handheld device is either a camera, a telephone, or a personaldigital assistant.
 7. An electronic device comprising: a plurality ofdata input keys, wherein each input key is associated with at least oneinput data value and at least one data input key is a multi-value keyassociated with at least two input data values; an eye-tracking systemfor determining an area where a user is gazing by monitoring an eyemovement of the user, wherein the eye-tracking system determines an areacovering portions of at least two data input keys, at least one of whichis a multi-value key; and an input value selection module coupled to theplurality of data input keys and to the eye-tracking system; wherein theinput value selection module determines which input data value wasentered based on a manually pressed data input key and on the area wherethe user is gazing.
 8. The electronic device according to claim 7comprising a plurality of defined gaze areas, at least one gaze areaoverlapping at least two multi-value keys.
 9. The electronic deviceaccording to claim 8 wherein each defined gaze area is associated withone input data value in each of a first and a second multi-value key.10. The electronic device according to claim 8 wherein each defined gazearea is associated with one input data value in each of a first, asecond, a third and a fourth multi-value key.
 11. The electronic deviceaccording to claim 9 wherein the input value selection module enters theinput data value that is associated with the gaze area and that isassociated with the manually pressed multi-value key.
 12. The electronicdevice according to claim 7 wherein the electronic device is a handhelddevice.
 13. The electronic device according to claim 12 wherein thehandheld device is either a camera, a telephone, or a personal digitalassistant.
 14. A method for processing data entered at an electronicdevice having at least one multi-value key associated with at least twoinput data values, the method comprising: assigning a plurality of unitsto each multi-value key, wherein each input data value corresponds to atleast one unit; determining an area where a user is gazing by trackingthe user's eye movement; detecting a manual selection of a multi-valuekey; and determining probabilistically an input data value entered basedon a value received from at least one unit and on the area where theuser is gazing.
 15. The method of claim 14 further comprising: assigningat least one pressure sensor to each unit of the multi-value key,wherein each of the pressure sensors is configured to measure andquantify a pressure asserted on the associated unit of the multi-valuekey; and concurrently analyzing the pressure measurements and the areaat which the user is gazing to determine which input data value wasentered.
 16. The method of claim 15 further comprising defining the areaat which the user is gazing as substantially coinciding with a unitassociated with an input data value.
 17. The method of claim 15 furthercomprising: assigning a pressure weight to each of the input data valuesassociated with the multi-value key, the pressure weight correspondingto measured pressured asserted on the unit corresponding to the inputdata value; assigning a gaze weight to each of the input data valuesbased on an amount of time that the area at which the user is gazingcoincides with the unit corresponding to the input data value; combiningthe pressure weight and the gaze weight of each input data value; andentering the input data value based on the combined pressure and gazeweights.
 18. A method for processing data entered at an electronicdevice having a plurality of data input keys, each data input key beingassociated with at least one input data value and at least one datainput key being a multi-value key associated with at least two inputdata values, the method comprising: determining an area where a user isgazing by tracking the user's eye movement, wherein the area coversportions of at least two data input keys, at least one of which is amulti-value key; detecting a manual selection of a data input key; anddetermining which input data value was entered based on the manuallypressed data input key and on the area where the user is gazing.
 19. Themethod of claim 18 further comprising defining a plurality of gazeareas, at least one gaze area overlapping at least two multi-value keys.20. The method of claim 19 wherein each defined gaze area is associatedwith one input data value in each of a first and a second multi-valuekey.
 21. The method of claim 20 wherein determining which input datavalue was entered includes identifying the input data value that isassociated with the gaze area and that is associated with the manuallypressed multi-value key.
 22. A computer readable medium containingprogram instructions for entering data using an electronic device havinga plurality of data input keys, wherein each data input key isassociated with at least one input data value and at least one datainput key is a multi-value key associated with at least two input datavalues, the computer readable medium comprising program instructionsfor: determining an area where a user is gazing by tracking the user'seye movement, wherein the area covers portions of at least two datainput keys, at least one of which is a multi-value key; detecting amanual selection of a data input key; and determining which input datavalue was entered based on the manually pressed data input key and onthe area where the user is gazing.
 23. A computer readable mediumcontaining program instructions for entering data using an electronicdevice having at least one multi-value key associated with at least twoinput data values; the computer readable medium comprising programinstructions for: assigning a plurality of units to each multi-valuekey, wherein each input data value corresponds to at least one unit;determining an area where a user is gazing by tracking the user's eyemovement; detecting a manual selection of a multi-value key; anddetermining probabilistically which input data value was entered basedon a value received from at least one unit and on the area where theuser is gazing.